# -*- coding: utf-8 -*-#
#-------------------------------------------------------------------------------
# 建立者:        潘炎珍  
# Name:         demo14
# Description:
# Author:       98745
# Date:         2019/3/12
#-------------------------------------------------------------------------------

import numpy
import matplotlib.pyplot as plt

x=numpy.linspace(-4,4,1024)
y=0.25*(x+4)*(x+1)*(x-2)
plt.title(r'$f(x)=\frac{1}{4}(x+4)(x+1)(x-2)$')
plt.plot(x,y,c='r')
plt.show()